Glaucoma is a major eye disease that arises from progressive damage to the optic nerve (ON) and retinal ganglion cells (RGCs) and their axons, the retinal nerve fiber layer (RNFL). If left untreated, it can lead to permanent nerve damage and blindness. Therefore, determining the rate of progression in glaucomatous patients is crucial in glaucoma management.
Progression can be detected using structural measurements (e.g., OCT measurements of the retinal nerve fiber layer (RNFL) and ganglion cell layer), or functional measurements (e.g., visual field exams), or both. Often times, but not always, progression can be observed by an OCT measurement, before the visual field is impacted. However, at later disease stages, no further RNFL thinning can be observed based on the OCT measurement (‘OCT floor effect’) and a visual field measurement may become the only metric to determine the change or progression.
The Cirrus HD-OCT™ (Carl Zeiss Meditec, Inc. Dublin, Calif.) is one type of commercially available spectral domain OCT (SD-OCT) system that can be used to provide structural measurements. The Humphrey HFA (Carl Zeiss Meditec, Inc. Dublin, Calif.) is one type of standard automated perimeter that can be used to provide functional measurements. Guided progression analysis has been available for both the Cirrus HD-OCT and HFA, however the analysis is currently separated by instrument type, and is only accessible independently from each other. No integrated view including both the structural and functional measurements on progression information from different systems is available, thus interpreting this data on separate systems is difficult and time consuming.
Therefore, there is a need for a method or technique that can display results of both the structural and functional measurements on a single screen or point of contact in an efficient way, so that their respective progressions can easily be compared to each other and assessed.